Airjet Spinning Arrangement

ABSTRACT

An airjet spinning arrangement includes a fiber feed channel, which runs into a vortex chamber, and a fiber withdrawal channel, which exits out of the vortex chamber. The fiber withdrawal channel is arranged in a spindle-shaped component, which can be moved away from the fiber feed channel by a moving device. In order to clean the area of the entry opening of the thread withdrawal channel, a cleaning channel is provided, which is directed against the spindle-shaped component and is connected to a pressurized air source. The cleaning channel runs into a ring channel, which surrounds the spindle-shaped component. A first exit opening of this ring channel is designed so that it forms a ring opening surrounding the spindle-shaped component and is directed against the spindle shaped component when the spindle-shaped component is moved away from the fiber feed channel. A second exit opening of the ring channel runs via an intermediary channel into the thread withdrawal channel and is directed against the entry opening of the thread withdrawal channel. Thus, the area of the entry opening maybe cleaned from the inside and the outside in the case of maintenance.

BACKGROUND AND SUMMARY OF THE INVENTION

The present invention relates to an airjet spinning arrangement including a fiber feed channel which runs into a vortex chamber, and also including a fiber withdrawal channel exiting out of the vortex chamber and having an entry opening. The fiber withdrawal channel is arranged in a spindle-shaped component. A moving device is provided for moving the spindle-shaped component away from the fiber feed channel and a cleaning channel having an exit opening directed against the spindle-shaped component is provided and is connectable to a pressurized air source.

An airjet spinning arrangement of this type is known from German published patent DE 195 01 545 C2. During the spinning process, a stable fiber band is drafted to a fiber strand in a drafting device arranged upstream, to which fiber strand the spinning twist is then given in the airjet spinning arrangement. In this process, the fiber strand is initially fed through a fiber feed channel of the airjet spinning aggregate into a vortex chamber, to which a fluid device for generating a vortex current around an entry opening of a thread withdrawal channel is assigned. The front ends of the fibers held in the fiber strand are hereby fed into the thread withdrawal channel, while rear free fiber ends spread out, are seized by the vortex current and twined around the front ends already located in the entry opening of the thread withdrawal channel, that is ends already intertwined, whereby a thread, having to a great extent real twist, is generated.

If for any reason the still very weak untwisted fiber strand or the spun thread breaks, a piecing process must take place, in which the end of the already spun thread is fed back to the drafting device. In the known airjet spinning arrangement, it is provided that after an interruption in the spinning process, the pressurized air exiting from the pressurized air nozzles is additionally cut off and a component including the thread withdrawal channel is moved away from the fiber feed channel. It is hereby necessary to clean the area between the fiber feed channel and the thread withdrawal channel, as, in the case of an end break, a tuft of fibers or threads can settle in the relatively narrow gap which exists between the fiber feed channel and the thread withdrawal channel during operation.

For the purposes of cleaning this critical area, a variation is disclosed in the above mentioned prior art, according to which a cleaning channel is provided, which then, when the spindle-like component is moved away from the fiber feed channel, blows a stream of pressurized air against the spindle-shaped component. It is, however, obvious from the examples of the embodiment that, due to the fact that the entry opening of the thread withdrawal channel is very far from the exit opening of the cleaning channel, a thorough cleaning of the critical area is not possible. This applies, in particular, when the thread withdrawal channel is blocked in the area of its entry opening.

It is an object of the present invention to avoid this disadvantage and to create a solution for an airjet spinning arrangement of the above mentioned type, which provides an effective cleaning process for the particularly critical area between the fiber feed channel and the entry opening of the thread withdrawal channel in the case of an interruption in the spinning process.

This object has been achieved in accordance with the present invention in that the cleaning channel runs into a ring channel, which surrounds the spindle-shaped component, of which ring channel a first exit opening—in the case of the spindle-shaped component being moved away from the fiber feed channel—is designed as a ring opening surrounding the spindle-shaped component and directed against the fiber feed channel, and of which ring channel a second exit opening runs via an intermediary channel into the thread withdrawal channel and is directed against the entry opening of same.

Due to the features of the present invention, a thorough cleaning of the area of the entry opening of the thread withdrawal channel from the outside and the inside is possible. On the one hand, the airstream coming out of the ring opening blows over the outer contour of the spindle-shaped component and to the fiber feed channel and cleans this area from the outside. On the other hand, a further pressurized airstream blows via the second exit opening of the cleaning channel from the inside, that is, through the entry opening of the thread withdrawal channel against the fiber feed channel.

As the spindle-shaped component of an airjet spinning arrangement is usually surrounded by an air evacuation channel, in which low pressure also prevails during a maintenance process, the fiber pieces blown away by the flowing airstream are immediately evacuated.

In an embodiment of the present invention, it is provided that the first exit opening is closed in the case of the spindle-shaped component not being moved away from the fiber feed channel. Therefore, when the spindle-shaped component is in its operational position, an airstream cannot flow over its outer contour even when the pressurized air is still activated. In this state, however, the pressurized air fed in via the cleaning channel can be fed via the intermediary channel into the fiber withdrawal channel, whereby this pressurized air can be given a further function in addition to the initial cleaning function, namely to suck in a thread end being transported back to the drafting device by way of injection and to feed it to the fiber feed channel. The connection to the pressurized air source is, therefore, first then disconnected from the cleaning channel when not only the cleaning process is completed, but when the thread end is fed back to the drafting device for the piecing process.

The first exit opening designed as a ring opening of the cleaning channel can, when the spindle-shaped component is in an operational position, be closed in a very simple way. The spindle-shaped component includes advantageously an area having a smaller outer diameter, which opens the ring opening when the spindle-shaped component is moved away from the fiber feed channel, and an area having a larger outer diameter, which closes the cleaning opening with a sealing gap when the spindle-shaped component is not moved away from the fiber feed channel. In this way, there is no need for a pressure valve, which results in cost savings.

BRIEF DESCRIPTION OF THE DRAWINGS

These and further objects, features and advantages of the present invention will become more readily apparent from the following detailed description thereof when taken in conjunction with the accompanying drawings wherein:

FIG. 1 shows a greatly enlarged depiction of an airjet spinning arrangement according to the present invention in axial intersection while in operation; and

FIG. 2 shows a view of the same airjet spinning arrangement of FIG. 1 in a non-operational state.

DETAILED DESCRIPTION OF THE DRAWINGS

The airjet spinning arrangement 1 shown in FIG. 1 serves to produce a spun thread 2 out of a staple fiber strand 3. A drafting device 4 is arranged upstream of the airjet spinning arrangement 1.

The staple fiber strand 3 is fed to the drafting device 4 in drafting direction A and withdrawn as a spun thread 2 in withdrawal direction B and guided to a winding device (not shown). The only partly shown drafting device 4 is preferably a three-cylinder drafting device and includes, therefore, three roller pairs, each of which includes a driven bottom roller and an upper roller designed as a pressure roller. Only the delivery roller pair 5, 6 is shown, which ends the drafting zone of the drafting device 4. In a drafting device 4 of this kind, a staple fiber strand 3 is drafted in the known way to the desired degree of fineness. Directly downstream of the drafting device 4, a thin fiber strand 7 is present, which is drafted and still twist-free.

The fiber strand 7 is fed via a fiber feed channel 8 to the airjet spinning arrangement 1. Downstream thereof lies a so-called vortex chamber 9, in which the fiber strand 7 receives its spinning twist, so that the spun thread 2 is formed, which is withdrawn through a thread withdrawal channel 10.

A fluid device generates a vortex current during the spinning process in the vortex chamber 9 by blowing in compressed air through compressed air nozzles 11, which run tangentially into the vortex chamber 9. The compressed air exiting out of the nozzle openings is discharged via an evacuation channel 12, whereby the channel 12 has a ring-shaped cross section around a spindle-shaped component 13, which is stationary during operation and which includes the thread withdrawal channel 10.

An edge of a fiber guiding surface 14, acting as a twist block, is arranged in the area of the vortex chamber 9, the fiber guiding surface 14 being slightly eccentrically arranged to the thread withdrawal channel 10 in the area of its entry opening 15.

In the airjet spinning arrangement 1, the fibers to be spun are, on the one hand, held together in a fiber strand 7, and thus fed from the fiber feed channel 8 into the thread withdrawal channel 10 essentially without a spinning twist, while on the other hand the fibers in the area between the fiber feed channel 8 and the thread withdrawal channel 10 are exposed to the vortex current. The vortex current causes the fibers, or at least their end areas to be driven away radially from the entry opening 15 of the thread withdrawal channel 10. The threads 1 produced by the above described airjet spinning arrangement 1 display a core comprising fibers or fiber areas extending essentially in thread longitudinal direction without any significant twist, and an outer area in which the fibers or fiber areas are wrapped around the core. An airjet spinning arrangement 1 of this type permits very high spinning speeds, which lie in the range of between 300 and 600 m per minute.

The compressed air exiting out of the compressed air nozzles 11 into the vortex chamber 9 is fed to the airjet spinning arrangement 1 during operation via a compressed air channel 16 in feed direction C. From the compressed air channel 16, the compressed air reaches first a ring channel 17, which surrounds the vortex chamber 9, to which the above mentioned compressed air nozzles 11 are directly connected.

During the operational spinning process, there exists a very small distance between the entry opening 15 of the thread withdrawal channel 10 and the fiber guiding surface 14, which small distance can measure, for example, 0.5 mm. This small distance x₁ is adjusted in that the spindle-shaped component 13 including the thread withdrawal channel 10 is arranged such that it is movable in an axial direction. The distance x₁ can be fixed by way of a spring in the operational state. In order to increase the distance x₁, as can be seen in FIG. 2 with the aid of a larger distance x₂, the spindle-shaped component 13 includes a piston-like component 19, whose function is described below.

When, for any reason, the fiber strand 7 or the thread 2 breaks, the compressed air being fed to the vortex chamber 9 is first cut off, see the crossed arrow C in FIG. 2. At the same time, all drives of the drafting device 4 and of the thread withdrawal rollers (not shown) and the winding device (not shown) are switched off. The upper roller 6 of the delivery roller pair 5, 6 is raised from the bottom roller 5.

Because the spindle-shaped component 13 includes a piston-like component 19, the spindle-shaped component 13 can be moved away from the fiber feed channel 8 using very simple means. Thus, a ring channel 20 surrounding the spindle-shaped component 13 is provided, which is connected to a conduit 21 for compressed air. This compressed air, see arrow D in FIG. 2, and the arrow crossed through in FIG. 1, is fed only when the spinning process is interrupted. The compressed air entering into the ring channel 20 moves the piston-like component 19 upwards as shown in the view in FIG. 2, so that the ring channel 20 increases due to the piston stroke to become an enlarged ring chamber 22. The piston-like component 19 thus borders the ring channel 20 during operation and the enlarged ring chamber 22 during an interruption of the spinning process. The compressed air of the so designed moving device acts hereby against the spring 18, which presses the piston-like component 19 into its secure operational position when the compressed air is cut off, that is during the spinning process. The moving away of the spindle-shaped component 13 from the fiber feed channel 8 is served by the compressed air fed via the conduit 21, while the spring 18 serves the return movement.

The very small distance x₁ is increased to a distance x₂ by moving away the spindle-shaped component 13, which permits the cleaning of the space between fiber guiding surface 14 and the entry opening 15 of the thread withdrawal channel 10 in a way described below.

Subsequently, a thread end for piecing can be fed back to the drafting device 4 in a way not shown in the opposite direction of the operational withdrawal direction B of the thread 2.

In order to clean the critical area between the fiber feed channel 8 and the entry opening 15 of the thread withdrawal channel 10, a cleaning channel 23 is provided, to which compressed air can be fed in feed direction E when required. This cleaning channel 23 is directed against the spindle-shaped component 13 with a number of exit openings in a way described below.

The cleaning channel 23 runs initially into a ring channel 24 surrounding the spindle-shaped component 13. Two exit openings 25 and 26 go out more or less directly from this ring channel 24. In the case of the spindle-shaped component 13 moved away from the fiber feed channel 8, a first exit opening 25 is designed as a ring opening surrounding the spindle-shaped component 13, which is closed in the operational position as shown in FIG. 1. The second exit opening 26 runs via an intermediary channel 27 in the thread withdrawal channel 10 and is directed against the entry opening 15 of the thread withdrawal channel 10.

The spindle-shaped component 13 can be cleaned from its outer contour up to the entry opening 15 of the thread withdrawal channel 10 via the exit opening 25 designed as a ring opening. The inside of the thread withdrawal channel 10 is cleaned via the second exit opening 26.

As mentioned above, the first exit opening 25, in the case of the spindle-shaped component 13 not being moved away from the fiber feed channel 8, is closed. This can be achieved in that the spindle-shaped component 13 includes an area 28 having a smaller outer diameter and an area 29 having a cylindrical, larger outer diameter.

When the spindle-shaped component 13 is moved away from the fiber feed channel 8, as shown in FIG. 2, the first exit opening 25 in the form of a ring opening is opened. When, in contrast, as shown in FIG. 1, the spindle-shaped component 13 is in its operational position, this ring opening is closed by way of a sealing gap 30 due to the diameter proportions. It is however, if required, possible to continue to blow pressurized air via the intermediary channel 27 and the second exit opening 26 into the thread withdrawal channel 10 against the fiber feed channel 8 and thus achieve that a thread end to be pieced is fed back to the drafting device 4 by injection action. In this way, a further function can be allocated to the cleaning channel 23.

It should be mentioned at this point that, if required, the pressurized air, which enters via the pressurized air channel 16 and serves as air for the spinning process, can also be fed in the non-operational position as shown in FIG. 2. The air then exits out of the pressurized air nozzles 11 and can additionally clean hereby the area of the fiber guiding surface 14 if this is required.

As can be seen, pressurized air can be fed to the airjet spinning arrangement 1 at three different places—each separately controlled—namely via the pressurized air channel 16, via the conduit 21 and via the cleaning channel 23. 

1-5. (canceled)
 6. An airjet spinning arrangement, comprising: a fiber feed channel which runs into a vortex chamber; a fiber withdrawal channel exiting out of the vortex chamber and having an entry opening, said fiber withdrawal channel being arranged in a spindle-shaped component; a moving device for moving the spindle-shaped component away from the fiber feed channel; and a cleaning channel having an exit opening directed against the spindle-shaped component and being connectable to a pressurized air source, wherein the cleaning channel runs into a ring channel which surrounds the spindle-shaped component, from which a first exit opening that occurs when the spindle-shaped component is moved away from the fiber feed channel is designed as a ring opening surrounding the spindle-shaped component and being directed against the fiber feed channel; and wherein from the ring channel a second exit opening runs via an intermediary channel into the thread withdrawal channel, the second exit opening being directed against the entry opening of the thread withdrawal channel.
 7. The airjet spinning arrangement according to claim 6, wherein the first exit opening is closed when the spindle-shaped component is not moved away from the fiber feed channel.
 8. The airjet spinning arrangement according to claim 7, wherein the spindle-shaped component comprises an area having a smaller outer diameter, which opens the ring opening when the spindle-shaped component is moved away from the fiber feed channel, and also comprises an area having a larger outer diameter, which closes the ring opening with a sealing gap when the spindle-shaped component is not moved away from the fiber feed channel.
 9. A component of an airjet spinning arrangement in which a fiber feed channel runs into a vortex chamber, comprising: a spindle-shaped component through which extends a fiber withdrawal channel, an entry opening of the fiber withdrawal channel being located at one end of the spindle-shaped component which extends into the vortex chamber when in use; and a cleaning channel arranged to have an entry opening on an exterior of the spindle-shaped component and an exit opening into the fiber withdrawal channel extending through the spindle-shaped component, whereby pressurized air may be directed toward the entry opening of the fiber feed channel from within the spindle-shaped component.
 10. The component according to claim 9, wherein the spindle-shaped component comprises an area having a smaller outer diameter operatively configured to open a ring opening surrounding the spindle-shaped component when the spindle-shaped component is moved away from the fiber feed channel, the spindle-shaped component further comprising an area having a larger outer diameter operatively configured to close, via a sealing gap, the ring opening when the spindle-shaped component is in an operational position of the airjet spinning arrangement. 